Computer electronic devices such as central processing units (CPUs) generate lots of heat during normal operation. If not properly removed, such heat can adversely affect the operational stability of computers. Solutions must be taken to efficiently remove the heat from the CPUs. Typically, a heat sink is mounted on a CPU to remove heat therefrom.
Modem heat sinks are usually made by aluminum extrusion method because of its relatively low cost of production. However, aluminum extrusion heat sink, which commonly includes a flat base and a plurality of fins extending upwardly from the base, has many drawbacks. The first drawback is that the total surface area of the fins available for heat dissipation is very limited as the made space between adjacent fins cannot be desirably small enough, and the ratio of the height of the fins to the space between adjacent fins is limited to a maximum value of 13:1. This drawback seriously bars improvement of the heat removal rate of the aluminum extrusion heat sinks. Another drawback is that the heat generated by heat sources cannot be rapidly transferred to an upper portion of the fins so that the upper portion of the fins has a relatively lower heat dissipation effect. This also limits heat dissipation efficiency of the heat sinks.
There is another kind of aluminum extrusion heat sink which includes a central post and a plurality of fins extending from the post. This kind of heat sink has a relatively large heat dissipating surface area because of incorporating more fins. However, the heat generated by heat sources still cannot be rapidly transferred to an upper portion of the heat sink, and the large heat dissipating surface area is therefore not efficiently used. Thus the heat dissipation effect of the heat sink is still not satisfactory. Taiwan Patent Issue No. 514488 shows an example of this kind of heat sink.
Therefore, it is desired to design a novel heat dissipating device to overcome the aforementioned problems and increase the heat dissipation effect thereof.